1. Field of the Invention
The present invention relates to a substrate body transfer apparatus and operating method therefor. In greater detail, the present invention relates to a substrate body transfer apparatus, and an operating method therefor, which is an apparatus employed when extracting or inserting thin plate-shaped substrate bodies employed in the semiconductor industry or the liquid crystal industry or the like from or into cassettes which store the substrate bodies, which is capable of extracting and inserting the substrate bodies while floating the substrate body on a gas.
2. Description of the Related Art
Conventionally, in manufacturing processes of semiconductors and the like, a substrate body conveyance apparatus is employed to move the substrate body (for example, a semiconductor wafer) between manufacturing apparatuses used in each process. Examples of this type of conveyance apparatus are, for example, conveyance apparatuses which convey a cassette jig, into which the substrate body is inserted, on a conveyance vehicle, and conveyance apparatuses which convey the substrate body one at a time using a robot arm. However, in these control apparatuses, the atmosphere in the space in which the substrate body is processed is the atmospheric air, and it is currently the case that such spaces do not have an atmosphere of sufficiently high cleanliness. Recently, methods have also been employed in which a cassette jig with a substrate body inserted thereinto is conveyed in a sealed container; however, the problems of contamination from the materials of the container and the gasket used to maintain air tightness with respect to the substrate body have not been solved.
An air conveyance apparatus which conveys the substrate body using air (an air bearing) within the conveyance path has been proposed as a method for solving these problems. In these air conveyance apparatuses, the conveyance path can be made a closed type (closed system), so that it is possible to make the surroundings of the substrate body a space having a sufficiently high degree of atmospheric cleanliness. In such a conventional air conveyance apparatus, functions such as long or short distance conveyance or divided path conveyance, flotation stoppage by means of hovering, determination of the direction of the axis of crystallization by rotation to the left or right, and the like, are completely provided; however, because this is fundamentally single wafer conveyance, the extraction of single substrate body (for example, semiconductor wafers) stored within a cassette had to be conducted by means of a transfer process wherein direct contact was made with the substrate body, an example of which is a robot hand (finger), or the like.
When the transfer mechanism described above is used, a method in which the rear surface of the substrate body is caused to adhere by vacuum, or a method In which the periphery of the substrate body is supported by a 1-shaped hand from the lower side thereof, have come to be employed. However, in the former case, the contamination of the rear surface of the substrate body becomes a problem, and this cannot be said to be optimal currently, when wafers, both sides of which are mirrored, are employed as the substrate body. Furthermore, in the latter case, there are problems with the chipping of the substrate body or with the attachment of particles which are deposited on parts of the transfer mechanism which support the substrate body.
The present invention has as an object thereof to provide a substrate body transfer apparatus, and an operating method therefor, which is capable of removing substrate bodies from, and inserting them into, cassettes by means of air conveyance, without employing a transfer mechanism such as those which make direct contact with the substrate bodies when extracting thin plate-shaped substrate bodies from, or inserting them into, cassettes; this apparatus is optimal for use as a single wafer processing type air conveyance apparatus.
The substrate body transfer apparatus in accordance with the present invention is a substrate body transfer apparatus which is employed when thin plate-shaped substrate bodies are extracted from or inserted into cassettes which store the substrate bodies, characterized in comprising: an air conveyance hand which is provided with a plurality of gas nozzles at a conveyance surface which opposes the rear surface of the substrate body and has the function of conducting the flotation or grounding of the substrate body, the catching or launch of the substrate body, or the centering of the substrate body; and a cassette platform which has a unitary structure comprising a cassette platform seat on which the cassette is placed and which is provided with a mechanism for horizontally advancing and retracting the cassette with respect to the air conveyance hand, and a mechanism for raising and lowering the cassette platform seat at a predetermined pitch.
Using the substrate body transfer apparatus described above, the operating method for transferring substrate body from the cassette in the direction of the air conveyance hand is provided with at least: a process for placing the cassette on the cassette platform seat; a process for disposing the air conveyance hand within the cassette by advancing the cassette platform seat in the direction of the air conveyance hand, and bringing the conveyance surface of the air conveyance hand into close proximity with the lower surface of a freely selected substrate body stored within a slot in the cassette; and a process for floating the substrate body by spraying a predetermined gas in the direction of the substrate body from predetermined nozzles provided in the conveyance surface of the air conveyance hand, and moving the substrate body from the cassette in the direction of the air conveyance hand.
Furthermore, using the substrate body transfer apparatus described above, an operating method for transferring substrate body from the air conveyance hand in the direction of the cassette is provided with at least: a process for placing the cassette on the cassette platform seat; a process for advancing the cassette platform seat in the direction of the air conveyance hand which conducts the floatation support of the substrate body, by spraying predetermined gas towards the substrate body from predetermined nozzles provided in the conveyance surface of the air conveyance hand, and accepting the air conveyance hand within a predetermined slot within the cassette; a process for stopping the spraying of the predetermined gas sprayed toward the substrate body from the predetermined nozzles provided in the conveyance surface of the air conveyance hand and inserting the substrate body into a predetermined slot in the cassette; and a process for withdrawing the air conveyance hand from the cassette by retracting the cassette platform seat in the opposite direction from that of the air conveyance hand.
In the substrate body transfer apparatus having the structure described above, the substrate body is supported in a floating state by spraying predetermined gas in the direction of the substrate body from predetermined nozzles provided in the conveyance surface of the air conveyance hand, so that the air conveyance hand, which is the mechanism for moving the substrate body, is capable of inserting the substrate body into and withdrawing the substrate body from the cassette without coming into direct contact with substrate body. Accordingly, a substrate body transfer apparatus is obtained which is capable of eliminating the problems of the contamination of the rear surface of the substrate body, the chipping of the substrate body, or the attachment of particles or the like which are deposited on parts of the transfer apparatus which support the substrate body. Furthermore, in accordance with the operating method described above, it is possible to insert substrate body into and withdraw substrate body from the cassette by using the substrate body transfer apparatus of the present invention.